1. Field of the Invention
The present invention relates to a solid-state imaging device, and in particular to a CMOS solid-state imaging device equipped with a global shutter function, as well as to a method of manufacturing the solid-state imaging device. The present invention also relates to a method of driving the solid-state imaging device, as well as to an electronic apparatus in which the solid-state imaging device is employed.
2. Description of the Related Art
In recent years, video cameras and electronic still cameras have been widespread. In these cameras, a charge coupled device (CCD) or amplified solid-state imaging device is employed. In the amplified solid-state imaging device, signal charges generated by and accumulated in the photoelectric converter section in a light receiving pixel are transferred to an amplifier provided in this pixel and an amplified signal is output from the pixel. A plurality of such pixels are arranged in a matrix in the amplified solid-state imaging device. Examples of amplified solid-state imaging devices include solid-state imaging devices employing junction field-effect transistors or complementary metal oxide semiconductor (CMOS) transistors in amplification sections.
In a typical CMOS solid-state imaging device in the past, the signal charges generated by and accumulated in the photoelectric converter sections in the pixels arranged in a two-dimensional matrix are sequentially read out row by row. In this type of solid-state imaging devices, exposure timing differs from pixel to pixel because the exposure timing in each pixel is determined by the start and end of readout of the signal charges in the photoelectric converter section in the pixel. Inherently, this type of CMOS solid-state imaging devices have a problem that a distorted image of a subject is taken when the subject is fast moving.
To address the above problem, in recent years there has been proposed a simultaneous imaging function (global shutter function) for simultaneous accumulation of signal charges, and there is an increased application of CMOS solid-state imaging devices equipped with the global shutter function.
The CMOS solid-state imaging device equipped with the global shutter function generally uses a light shielded accumulation capacitor section to accumulate the signal charges generated by the photoelectric converter section until they are read out (see Japanese Unexamined Patent Application Publication No. 2004-111590, for example). In such CMOS solid-state imaging devices in the past, after all pixels are simultaneously exposed to light, the signal charges generated by the photoelectric converter sections are transferred to the accumulation capacitor sections simultaneously in all pixels, accumulated there, and sequentially converted into pixel signals at a predetermined readout timing.